


the time their age gap got wider

by kakkoweeb



Series: Pomp or Circumstance [3]
Category: Haikyuu!!
Genre: Daa Daa Daa AU, Gen, M/M, explanation in the notes, scandalous title lmao
Language: English
Status: Completed
Published: 2017-05-16
Updated: 2017-05-16
Packaged: 2018-10-30 14:14:05
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 5,577
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10878480
Author URL: https://archiveofourown.org/users/kakkoweeb/pseuds/kakkoweeb
Summary: Kageyama can be such a baby sometimes.--“I want the fact that I existed to mean something.”– ChapinOiKage Week Day 3





	the time their age gap got wider

**Author's Note:**

> god u guys oikage is so pedophillic and gross if u ship it ur a pedo and a shitstain of a human being and u can go die in hell srry not srry i don't make the rules
> 
> i'll explain the au in the end notes as usual but as a little primer: in this au, oikawa and kageyama live together for a ridiculous reason and every character in hq goes to the same school. yup. sounds like fun, don't it. also this is the most dialogue-heavy piece i've had to write in a while and i joined like 3 new discord servers and god was this hard to finish.

If you’d talked to Oikawa about the worst, craziest thing he could see while wandering around on his first Saturday off in a long time and suggested dragons and the undead and whatever else media these days dictated would bring the end of days, he’d have hummed contemplatively, maybe even agreed with you. However, if you’d said something along the lines of—say, a twelve-year old who looked exactly like Kageyama obliviously eating mitarashi dango in the middle of a crowded shopping mall he’d ask you to take less sugars in your coffee before changing topics, maybe something a little lighter, something less frightening.

Unfortunately, one fateful Saturday afternoon, that was exactly what he’d gotten.

“ _Tobio-chan,_ ” he cried, nothing short of appalled.

Kageyama looked blankly up at him as he chewed, but recoiled at least, perhaps upon noticing that Oikawa was over a foot taller than he was. “Oikawa-san?” he cried in turn, staring at Oikawa from head to toe, the half-chewed dango still resting inside his mouth. “How did you get so tall?”

“ _Me?_ How did _you_ get so small?” said Oikawa, grabbing Kageyama by his (little—oh god, they were so small) shoulders and situating him next to a particularly tall potted plant, the top reaching just a tad lower than Oikawa’s eyes. “Look at this! You’re literally shorter than this potted plant!” Kageyama had to greatly tilt his head to see the tip of the highest leaf, looking troubled, but that wasn’t all. Oikawa stared at his face, a little less hard-set than what he was used to. “You look younger too, like—more baby-faced.”

Cuter was the right term for it, but Oikawa was content with holding back his smile and keeping the word to himself.

Thoroughly disturbed now, Kageyama’s tiny body (seriously, he looked like he’d been suctioned and wrung dry of all the milk he’d drank over the years and the growth that came with it) moved around, relentlessly searching for something, until it was finally settling in front of a clear shop window. Oikawa followed after him, just in time to see his face contort in utter horror. “What the hell?” he yelled. At the very least, his current voice didn’t hold any significant differences from his real one. “What the _hell.”_ And neither did his choice of words. “What the—what happened to me? I look like a middle schooler!”

“That’s what I’m saying!” Oikawa chimed in, staring at his and Kageyama’s reflections on the glass. They looked like a pair of brothers out for a fun day on the town, and this time, Oikawa couldn’t help but giggle at Kageyama’s small, slightly chubbier infuriated face, and the strands of his hair that seemed to be floating up out of aggravation. He poked at the little boy’s cheeks. “Can’t say I’m disappointed, though, damn. I don’t remember you being this cute at twelve.”

“Shut the fuck up.”

“Tobio-chan, language! Junior high first years shouldn’t say words like ‘fuck’.”

“Fuck, fuck, fuck you,” Kageyama spat, and a group of middle-aged ladies passing behind him shot the both of them scandalized looks. Oikawa glanced apologetically at them. “How did this happen? How do I get back to normal?”

“Like I’d know. What did you even do all day?”

Kageyama paused, seemed to think. “I woke up, I had breakfast, took a shower, read a magazine, and then I got dressed and left to get dango.”

Of course he deliberately left home just to get the dango; Oikawa rolled his eyes. “And you’re sure that’s it?”

“I think so—wait. I saw a box of cookies on the dining table and I took a piece.”

“What box of cookies?”

“I dunno either. It was just there. It had this weird picture of an angel cartoon holding a cookie and it said, ‘Child Cookies’.”

“Child Cookies?” Oikawa repeated. He stared down at the top of Kageyama’s head, hesitated. “What’s that supposed to mean?”

“I don’t know. I figured it just meant cookies for kids or something.”

“But what if,” Oikawa said, “what if it actually means cookies that turn you into a kid? What if—if you eat the cookies, you get three years younger or something?”

Given their circumstances it wasn’t far-fetched; Kageyama’s face seemed to sink further into outright fear, and that Oikawa was able to tell was honestly amazing, given that the tiny child’s eyebrows were still furrowed like he wanted to kick somebody. Perhaps he did. “But if that’s the case,” he then said, “how do I turn back?”

“Maybe we need to find, like, adult cookies or something,” Oikawa suggested.

“That’s the dumbest thing I’ve ever heard.”

“You rude little—do you want my help or not?” Oikawa demanded, crossing his arms, huffing self-righteously when Kageyama fell silent, pouted like a child. It suited his current form. “Fine. How about we get you back home and find those cookies your gluttonous ass couldn’t leave alone and try and see if there’s any info on the box that might be useful? Does that sound okay to you?”

Kageyama made a face. “I guess it’s not so bad.”

“Everyone’s a critic.”

Begrudgingly resigning himself to the fact that his day off would have to be cut short, Oikawa crossed his arms and walked alongside Kageyama, still eating dango like an unrefined hooligan despite the fact that he was twelve and would possibly be forever. “Literally _where_ do you get all your chill?” he demanded, rolled his eyes when Kageyama simply looked up at him and licked his lips. “You do realize you’re not your age right now, right? You could care a little bit more about that.”

Almost as if to further illustrate the exact number of fucks he had the ability to give, the kid shrugged. “We just have to get home as fast as possible and it’s not like it can get any worse than this,” he said. “All we really have to do is make sure nobody sees me as a kid, but what are the odds of running into people from school here of all places?”

“Well, yeah, I guess that’s true,” Oikawa muttered, crossing his arms once again as they continued to walk; Kageyama moving a little bit faster, he noticed, probably to appease the anxiety he seemed to be feeling harder than the actual person with a predicament. Perhaps Kageyama was right: it didn’t seem all that bad, really, whatever the hell this was. It was certainly a cut below intergalactic kidnappers or getting their faces stuck together in the middle of a get-together with friends. And unlike with stupid kidnappers, hopefully, the fix wasn’t going to be that hard to find.

And right as he thought that, there was a distant but far too close for comfort call of, “Oikawa!”

Oikawa felt punched in the gut. Kageyama dropped his dango (but caught it in time).

Smiling as best as he could despite the involuntary gritting of his teeth, Oikawa kept a steady hand on Kageyama’s shoulder, imploring him not to make eye contact with whoever was interrupting their smooth-sailing mission, and turned around. Still involuntarily, his smile stretched wider. “Sawamura-kun,” he cried too happily, and Kageyama flinched, “and Suga-chan and Azumane-kun! _What_ a pleasant surprise! Enjoying the weekend together?”

“You could say that,” said Sawamura, jerking a thumb towards his best friends. “Asahi here said he needed help picking a birthday present for his dad.”

“Ooh, happy birthday to him!”

“Thanks, Oikawa,” said Azumane.

“Who’s this you have with you?” Suga asked, smiling down at Kageyama’s back.

Oikawa felt his eye and Kageyama’s shoulder twitch at the same time. “Who?” he asked, voice pitched higher than normal.

“Um, that little kid?”

“Which one?”

“The…one you’re holding on to?”

_Damn it._ Oikawa glanced at Kageyama, now trying to resume the consumption of his dango, stiff and tense enough to seem constipated. “Ahh, this? I mean—him? This little guy? Oh, he’s just—“ Kageyama Tobio, three years younger because he couldn’t keep his hands to himself; why do you ask? “—my um. My sister’s—cousin’s—best friend’s—husband’s—uh, nephew.” He grinned, swallowed, sweated. “Yeah, that’s him alright. Taking him out for a little, uh—bonding time.”

“Wait,” Sawamura said, appearing puzzled, “your…sister’s cousin’s best friend’s husband’s nephew?”

“Twice removed,” Oikawa added, ignoring Kageyama’s small mumble of, “What the fuck?”

“Wouldn’t your sister’s cousin also be your cousin?” Azumane asked.

Oikawa couldn’t breathe. “Y—yeah, I—I guess? I just…it’s—a bit of an inside joke we have going on. Family and all that. Close-knit.” Somebody please kill him. “And I would love to tell you three the story, but we should really be—“

“Why won’t he look at us?” Suga piped up again, and Oikawa had just about _had it_ with his questions.

He tried to steady his grin. “Oh, uh, he’s…” A miniature version of a guy you see on the regular and you’re not allowed to know that. “…ugly.”

Kageyama stomped on his foot.

“OW!”

Suga laughed. “It doesn’t seem like he agrees with that. Come on, little guy, you can turn around. I’m sure you’re not ugly. Oikawa’s just a big meanie, isn’t he?”

Too busy catering to the throbbing pain ( _damn_ , Kageyama had to be the strongest twelve-year old known to man) and trying not to start sweating out of his eyes, Oikawa could do nothing as Kageyama swallowed, breathed out, and slowly turned to his upperclassmen with a smidgeon of dango sauce right next to his lips. Oikawa had half the mind to take all of the remaining sauce and scatter it all over his face in the hope of rendering him unrecognizable, but that plan was out the window the moment all three of their harassers (for the lack of a better word; Oikawa felt pretty harassed at the moment) jumped in surprise.

“Oh, whoa,” Sawamura said, “he looks exactly like Kageyama.”

No shit, Oikawa was inclined to think, but he simply stood up straight and pretended to examine his sister’s cousin’s best friend’s husband’s nephew twice removed's face. “Really?” he asked. “I don’t see it.”

“How can you not see it? This kid’s like Kageyama with a different aspect ratio!” Suga cried.

“What’s your name?” asked Azumane, bending down with his hands on his knees to get a better view of Kageyama’s face.

“Oh, uh,” Kageyama said, at the very least giving effort to changing his voice, “I’m um. Sato…” The generic Japanese surname; alright, fair enough. “…Norio?” And the guy from the exam question; absolutely perfect, Oikawa totally didn’t want to melt into a puddle of goo and drift into the sewers.

Azumane blinked at him, and Suga let out an uneasy laugh. “That’s…an interesting name,” he said. “Are you having a good time with your Oikawa-nii-san?”

That definitely sounded good on the ears, but Oikawa-nii-san had a bad feeling about the blank, unfeeling look Kageyama was giving him. He laughed out loud, wrapped his arms around the entirety of Kageyama’s head, obstructing his speaking and possibly his breathing. “Of course he’s having a good time; I’m great with kids and the best tour guide anyone could ever ask for—right, _Norio-chan?”_

“Hmmhgm.”

“Ahh, the beautiful sound of acquiescence,” Oikawa said, nodding heartily to himself. “See? There’s nothing for you to concern yourselves about, friends, so if you don’t mind, Norio here and I have a really big to-do-list to cover so—“ Kageyama’s head gradually slipped from his hold “—Norio-chan, don’t run away from my love—”

But if the gaping faces of Sawamura, Suga, and Azumane were any indication, Norio hadn’t just simply struggled and gotten past his crushing grip. And when Oikawa looked down, it had taken all of the discipline he’d cultivated over the years—perfecting his sets and serves, acting sweet around girls, charming his parents’ esteemed guests—not to scream bloody murder.

Kageyama had shrunk. Norio now looked eight.

_“OKAY,”_ Oikawa did eventually yell out before anyone else could, grabbing Kageyama’s waist and hoisting him up as quickly as humanly possible, “WE HAVE _REALLY_ GOTTA GO. NICE SEEING YOU THREE, HAPPY BIRTHDAY, BYE!”

And he hobbled away.

 

 

It was a few blocks later that Oikawa had finally allowed himself to stop to catch his breath, but his desire to yell didn’t help the endeavour very much. “ _What the fuck,_ ” he cried, chest heaving, arms aching, cheeks stinging. _“Did you just—did you just get even younger? Is this just going to keep happening?”_

“I don’t know!” Kageyama shouted back, and _Jesus Christ,_ his voice was higher than Oikawa’s ex-girlfriend’s had been and he was quickly covering his mouth, face dripping with disgust and a bit of dango sauce.

“Holy shit,” Oikawa said, “holy shit, Tobio, we have to get you home. You’re so _small_ , oh my god, we have to get you home.” He sat on his heels to try and get a better grip on Kageyama’s waist instead of just recklessly keeping him above the ground and hoping for the best, but Kageyama moved away.

“Hey! You don’t have to carry me; I’m not a baby.”

“ _Um,_ in case you haven’t noticed, _you are._ ” Oikawa gestured to the (miniscule) entirety of Kageyama’s current physical structure. “I can’t let you walk on the streets when it’s this crowded and you look like a gremlin! Anyone could step on you and I’d just find a puddle of muck on the ground with your face on it.”

“No, you won’t, you dumbass! I can walk just fine and no one’s stepping on me without getting a foot in the b—“

“ _Don’t say it,_ you profane dwarf!” Oikawa cut in, standing back up and electing to get a good hold on Kageyama’s hand instead. “There, that’s fine, right? Don’t let go of my hand. If you so much as loosen your grip, I’m telling the police you’re a missing person. Got it?”

Kageyama grunted.

“Good. Let’s go.”

Now tightly-holding Kageyama’s hand and briskly walking him through the streets instead of sauntering beside him, Oikawa felt a little less relaxed. Actually, no, he felt as though any ounce of relaxation he could boast he’d ever felt was back with Sawamura, Sugawara, and Azumane—who were all probably exchanging conspiracy theories and gossip about him being a weirdo, but be that as it may, it didn’t change the fact that Kageyama looked eight instead of twelve and fifteen and there was no way of knowing whether this was the level where it truly stopped and yet it _needed_ to be stopped, very much so. If they let it carry on, Kageyama would get younger and younger, and who would be left without any coherent way to explain why he would no longer be able to attend his classes? Oikawa.

Of course, there were other problems that might spring forth as an end result to the predicament, but he’d rather not think about them at this point.

Most of his Saturdays, he spent holed up in the school gym for practice, and so the degree of people walking the streets was both surprising and overwhelming, to say the least, most especially because all of them seemed to be equally in a rush to get to wherever. Still, no matter how short his legs became, it seemed Kageyama would never have a hard time keeping up with him and the pace at which he moved forward. Oikawa stole a glance; he seemed a little red in the face, seemed to be taking laboured breaths, but otherwise alright.

As usual, however, life wasn’t about to let them off that easily. The more ground they covered, the thicker the gathering crowd seemed to become. People of all ages all made their way through the streets and in different directions, made it harder for Oikawa to craft a way through. He squeezed himself through the mass of bodies, hoping that the child he had on his hands wouldn’t get too overpowered—or worse, crushed.

“Doing okay down there?” he asked.

“Shut it, you’re not _that_ far up,” Kageyama spat back.

“Why the hell are there so many people out here anyway?”

“Didn’t you see the flyers? There’s a sale everywhere today! Half price or less for all goods in the city.”

“ _What?_ Does that really happen?”

“Apparently. That’s why I went out for dango.”

Oikawa groaned, ready to launch an entire barrage of reasons why holding a half-price sale _everywhere_ was the worst idea anyone could possibly come up with, but far too quickly he was colliding with an older woman holding three whole bags of oranges and far too quickly all of said oranges were falling to the ground, the woman was crying out in horror, and the surrounding people were either hopping over fruit or brutally murdering them.

“Oh my god, I’m so sorry!” Oikawa cried, falling to the floor himself and gathering together what oranges he could still salvage.

“My oranges!” the woman wailed.

“Yeah, I know, I’m so sorry, here I’m picking them all up for you, see?” Oikawa replied in his most concerned voice, grabbing onto orange after orange and returning each one into the slightly rumpled-up paper bags. He lifted and handed them back to her with a crooked, apologetic grin. “I’m sorry, I’d help you carry them back home—“ He glanced at Kageyama, at nothingness “—but I really have to get my nephew to—“

His head snapped down, took note of the empty space where Kageyama should have been. “Tobio?” he called, spinning around where he stood scanning his immediate surroundings for an eight-year old with an attitude. “Tobio? Tobio! Where the—oh my god—“

Without further regard to the woman scowling at her now tainted oranges, Oikawa whirled around, scanning the seemingly never-ending pool of heads and faces. “Tobio? Where are you?” he called, squeezing himself through people he’d already passed and would have never had to pass again had Kageyama just stayed where he was. “Tobio! Uh—I mean, Norio! Norio!”

“Yes?”

“Uh, no, not you. Sorry.”

He circled the entire area, got in between friends and lovey-dovey couples, considered dropping to the ground and crawling there to match Kageyama’s height, thought better of it, screaming out the ridiculous name, “Norio! Norio-chan?” all the while. And when that didn’t work, he’d outright grabbed people by the shoulder, desperately asking, “Have you seen an eight-year old with a stupid head and dango on his face somewhere?” and getting a shake of the head or a questioning glare each time.

“Ohh, god,” Oikawa groaned, pressing his hands to his face and stretching it thin, perhaps in the hope of getting a wider field of view, and constantly glancing around. “Norio, you idiot, where are you?”

He walked on, vision beginning to spin from how often he’d been snapping his head in any and all directions trying to find his missing nephew (a short version of the actual relation), still once in a while halting people to ask for their help in the most coherent way he, at this point, could.

“Hey, have you seen a kid around here? Black hair, stupid face, all that?”

“No, sorry.”

“Excuse me, have you seen a kid with dango sauce on his face anywhere?”

“I haven’t.”

“Have you seen my eight-year old?”

“No, but I bet he’s lovely, sir.”

“Kid. Dango. Seen him?”

“Uh, no?”

Oikawa roared, dropping to his knees in the middle of the road, taking in what he felt like were his last couple of breaths before his untimely demise. Of all the times to go missing, of all the _places_ , it had to be in the middle of an unrealistic sale that made absolutely no sense. Kageyama—whether as Tobio or Norio—truly was the expert at making Oikawa’s life a living hell. He wondered how long it would take for him to get towed away if he just dropped himself flat on the ground and didn’t move.

“Hey,” said some random person; Oikawa looked up at him, “you’re the guy who’s been going crazy looking for an eight-year old around here right?”

“Don’t remind me.”

“I saw him just earlier.”

“ _What._ Where?” Oikawa hopped to his feet.

“He was getting escorted by a cop.”

“ _What?_ But he’s just a kid! They can’t arrest him!”

“Uh, I was thinking more like they were going to take him back to the station and announce him as a lost child.”

“Oh. Yeah, that makes more sense. Thank you!” Oikawa said, performing the quickest ninety-degree bow known to man, and then running ahead to the only nearby station, thinking finally, _finally_ something today was going to go right and they were finally going to get home and find the box and get Kageyama back to normal.

His years of running up hills and diving to the ground and jumping for balls were finally paying off, and though he was, by all accounts, mentally and emotionally drained, his physical strength was in no way wavering and soon, the police station was coming into view. He took several deep breaths as he ran, more to calm himself down than to improve his endurance, made sure to wear a charming grin as he poked his head through the station door to ask for pardon for his intrusion, to ask if he could take custody of the missing eight-year old—but this grin was punched away from his face when he peered inside the station and found no such eight-year old.

There was, however, a toddler.

Oikawa screamed.

 

* * *

 

 

Whereas the rest of the day had been incredibly loud, crazy, and hectic, now there was nothing but tense silence. Oikawa’s scream hadn’t given the local police any reason to trust him but Kageyama, at least, made it a point to seem very adamant to leave with him and they’d gotten home without any further hitch. The box of cookies, however, proved to be no help at all, only gave them an affirmation that anyone who consumed the sweets would lose age more and more unless the phenomenon was countered with ‘Adult Cookies’ (which meant that Oikawa had been right, but it didn’t seem right to gloat to a little boy who could barely formulate his sentences) and that there was nothing else they could do.

That had been too many moments ago. Now, Oikawa was seated in Kageyama’s room, Kageyama himself—now an infant with barely any hair or attention span—soundly sleeping on the laid out futon. Oikawa kept the room dark, save for the minuscule light that came from the afternoon sun through the small gaps in the window and the illumination offered by the candles he’d lit by Kageyama’s most prized photo of his late mother over by the altar. It made things seem tranquil somehow, but it didn’t chase away the weight of the dread sitting in Oikawa’s chest.

Kageyama was so small, so silent, so fragile—everything he wasn't supposed to be. Seeing him made Oikawa want to snap photos, but his body wouldn’t move, and he couldn’t order it to do something so light-hearted when everything else felt so grim, when he didn’t know what would happen in a few hours, maybe a few minutes' time, and when he felt terrified out of his mind.

Part of him wanted to believe it wouldn’t be so bad. So maybe Kageyama was but a few months old right now and maybe he would stay that way for a long time, or perhaps until he was ready to start growing all over again. That would be fine, Oikawa told himself, staring at Kageyama’s innocent face and too-small hands. It was going to be difficult to explain but he would make do, they always did, and Oikawa would do his best to care for him, to get him back to the way he was before, no matter how long it took.

It was going to suck, Kageyama being different. But as long as he was alive, it was going to be okay.

But that was another thing, Oikawa remembered, and he gripped tightly onto the small blanket he’d laid out on top of Kageyama’s sleeping form. If Kageyama were to stay this way and end up needing to grow again, it would be difficult but it would be acceptable at least. But what was Oikawa supposed to do if he faded from existence altogether, if suddenly he would look down and find an empty space where the baby had been lying? The thought of it made him cold.

Kageyama—Tobio—was a lot of things. He could be annoying as hell, the worst person to have around in an emergency, an absolute brick with no feelings—but for all his faults, he was an important part of Oikawa’s life, something like a basic necessity of his day to day. To lose him so suddenly and to something like this would be indescribable, made him bite his lip, made him want to burn the image of Kageyama’s face, what it once was and what it was now, into his brain in the hope that he might never forget it.

Oikawa breathed in, wished he’d taken the situation a little more seriously when it had first sprang up. But all he could really do now was take Kageyama’s frail little body into his arms and hold him close.

“It’ll be okay, Tobio-chan,” he whispered, stroking the top of the baby’s head. “You’re not gonna disappear. We’ll get you back to normal.” He swallowed. “Yeah, maybe—it’ll take take a few years but soon you’ll be your dango-eating, volleyball-playing, profane self again. You’ll be like the little brother I never had. We’re gonna have a lot of fun and I’m gonna get to see all your dumb baby faces and I’m never gonna let you get taken by the cops ever again.” He gave a shaky laugh. “Sounds good, right?”

He looked down to examine Kageyama’s sleeping face once more, only to find him awake and blinking curiously up at him, eyes still half-lidded, tiny hand closed around the fabric of his shirt—and he breathed in, let out another shaky laugh, blinked back tears.

“Shut up, I’m not crying,” he said, using a single hand to rub at his eyes. “It’s gonna be so different without you, though.” He swallowed again, smiled down at Kageyama. “I think I’m actually gonna miss you.”

He sniffled once, his shoulders bouncing suddenly, and all of a sudden Kageyama’s lips were quivering and he was wailing, his grip on Oikawa’s shirt tightening as tears fell down his face. Oikawa himself shook. “Come on, don’t be a baby,” he said, pressing Kageyama closer but not holding him any tighter, too afraid to crush him.

“Don’t be a baby,” he said again.

Kageyama’s mother looked on from her frame.

“ _Okay,_ seriously, don’t cry, Tobio-chan, come on, you’re not making this any easier,” Oikawa begged, using the discarded blanket to mop Kageyama’s face dry of tears despite his own acquiring a few. He bounced the tiny body in his arms, tried to think of a song to sing, remembered that Kageyama always claimed to hate his singing and so decided to hum instead. It seemed to work; the incessant screaming mellowed down to significantly softer whines and sobbing, Kageyama squishing his own cheek against Oikawa’s chest and distorting his tear-streaked face.

Oikawa didn’t bother stifling his giggle. “Oh my god, that’s illegal,” he said, poking at the soft skin and receiving no complaints in return. He breathed in, breathed out. “Okay. This is going to be cheesy as hell, but this—this just feels so severe I feel like I have to get it out of the way.” He held Kageyama up a little higher, high enough to be able to plant a quick kiss on his forehead, before embracing him again. “I’m sorry—that this had to happen to you. I’m sorry we didn’t get to fix it, and that I’m such a—bad senpai and I couldn’t help. If—If you don’t disappear, I swear I’ll make it up to you. I’ll teach you to serve! You know, when you’ve got the arm strength. And—and—I’ll feed you lots of milk so you grow even taller than your moon friend and Kindaichi and that weird-looking Russian. And when your dad gets home I’m gonna tell him off for leaving for India all the time and I’m gonna tell him to stay with you forever and be a responsible parent. I’ll light your mom’s candles for you. And—and—“

He swallowed, yet again, closed his eyes. “I want you to know…even though you’re a pest most of the time…that you’re—awesome. And I’m proud of you and how good you are and I know you’re gonna make the National team in, like, twenty more years. And though I always try to piss you off and succeed half the time, I hope you remember…that I care about you. And—“ Kageyama seemed to shift in his hold, seemed to get a little bit heavier “—though it’s not obvious, I actually— _what the—_ “

The weight in Oikawa’s arms quickly got heavier and heavier until he felt himself roughly falling on his back to the ground, entire body straining with effort to endure the load nicely settled on top of him. He cringed as the back of his head collided with the floor, grateful that it had landed on the mat and not the wood, and opened his eyes to reclaim his bearings and examine just what the hell was happening now.

And what was happening was that Kageyama’s face was right before his, fifteen and absolutely stunning.

Oikawa involuntarily gasped, his nose making an ugly whistling noise, but for the moment he would let it slide. Kageyama was no longer a baby and though he was heavy as fuck, Oikawa didn’t care; he tightened the hold he already had on Kageyama’s waist, muffled his scream into his chest, and rolled them around until they were off the futon and hitting the wall, Kageyama still ending up on top of him and wincing at his own arm.

“Ow,” he muttered, but Oikawa didn’t hear it.

“Oh my god, oh my god, you’re back. You’re not a baby, I don’t have to raise you, _holy god_ , thank you, you’re back, _thank you, oh my god._ ” Oikawa finally moved his arms so his palms could cover his face, could wipe away the excess tears still sitting by his eyes and on his cheeks, infinitely _glad_ , so glad, that whatever unseen entity had been watching over them all this time had heard his incoherent rambling and answered it like a prayer: Kageyama hadn’t disappeared. He was back and he could live his normal life and he wouldn’t leave Oikawa alone in the house with the alien baby and mutant cat babysitter.

He was also still on top of Oikawa, staring at him with an almost solemn expression, and when their eyes locked, Oikawa stilled—only for a good few seconds, however, until he was rapidly reddening like a cherry and yelping, slamming his hands against Kageyama’s upper body with the same strength he would use on a volleyball and sitting up, backing up against the wall as Kageyama screamed, fell to the side, rolled away.

“You—you maniac!” Oikawa cried.

“How am _I_ the maniac?” Kageyama yelled back, angry but without bothering to hide the splotches of warm colour on his own face. “You’re the one who kept talking about raising me like some—weirdo—“

“Shut up, oh my god, don’t mention that.”

The corner of Kageyama’s mouth quirked up. “Oh, you mean you don’t want me to talk about how you’re gonna miss me?”

“ _Holy shit.”_

“And that you’re gonna feed me milk and teach me to serve and—“

“Shut up; I can _not_ believe this—“

“—that you’re proud of me and that you care about me?”

“Nope, I take all of that back, I hate you and you can go sink in a hole.”

“Save it,” Kageyama said, that stupid sadistic smile still on his face. “What was that last thing you were gonna say, by the way?”

Oikawa felt his heart skip a beat, but he only frowned further. “Like hell I’m gonna tell you now, you ungrateful shit,” he snapped, getting to his feet and picking up the blanket he’d used for (the far more pleasant and lovable) baby Kageyama, rolled it up and threw it at (the older, stupid, annoying) older Kageyama. “Drown in your stupid baby tears.”

He pulled the sliding door open, ready to march ahead to anywhere he could scream his head off for oversharing to a baby with an apparently excellent memory, but stopped when he heard Kageyama, in a calm, serious voice, call: “Oikawa-san.”

His face when Oikawa turned was yet another Oikawa wanted to etch into his memory to preserve forever. “Thank you,” he said, earnestly.

Oikawa’s hand on the door frame trembled, a single finger tapping impatiently on the wood. He glanced away, played with his lips. “You’re welcome,” he grumbled, “now do me a favour and burn those cookies until they’re nothing but ash, tie them in a bag, and throw them in the Marianas Trench.”

Kageyama wore a small smile of agreement, and Oikawa only barely returned it before leaving the room and continuing his search for a place to freak the fuck out.

 

 

**Author's Note:**

> [CHILD COOKIES/DAA DAA DAA AU]
> 
> okay, about daa daa daa. it's a pretty old anime (on animax in my country, it was actually called UFO Baby) centered on the concept of an alien baby ruu and his babysitter wanya (a fat cat that stands on 2 feet stubs lmao) who accidentally made it to earth, landing in the house of miyu and kanata, two unrelated 14 year olds who wound up living together and alone because all their parents are immature idiots. it's kind of a stretch but it's my childhood and very entertaining and it has a special place in my heart. it's a romcom, kinda, and this fic is your first (and maybe only) taste at how random the series can be. originally, this piece was just going to take the child cookies concept, but while writing i thought 'holy shit? oikawa and kageyama fit miyu and kanata kind of well??' so it became full-blown daa daa daa au and now i've been given more ideas and now i kind of wanna write more chapters to this. a collection of shorts or something. 
> 
> also pls look at this [art](https://twitter.com/b160318/status/815942544404004864) it's hella cute
> 
>  
> 
> [feel free to talk/ask about this au and the anime, if you're curious!](http://kakkoweeb.tumblr.com/)


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